Ajay Solleti

It's already configurable. Refer to the [documentation](http://cdn.rawgit.com/paultuckey/urlrewritefilter/master/src/doc/manual/4.0/index.html#filterparams)

You can put up a pull request for the feature. You could potentially use the information in the [documentation](http://cdn.rawgit.com/paultuckey/urlrewritefilter/master/src/doc/manual/4.0/guide.html#extending) to extend the API to implement custom rules.